1. Unit 3: Mathematical Models
MAP4C
Unit 3: Mathematical Models

2. One Variable Data A variable is an attribute that can be measured.
One-variable data sets give measures of one attribute.
One-variable data can be analyzed using mean, median and mode.
You can recognize this when you see:
Tally charts
Frequency Tables
Bar Graphs
Histograms
Pictographs
Circle graphs

3. Two Variable Data
Two-variable data sets give measures of two attributes for each item in a sample.
You can recognize 2-variable data when you see:
Ordered pairs
Scatter plots
Two column tables of values

4. Recognizing Data Types
State whether each situation involves one or two-variable data. Justify your choice.
Noah researches annual hours of sunshine in Canadian cities.
A study compares the length of time children spend playing video games and the time they spend reading.
a) As this data can be analyzed with mean, median or mode: this is 1-variable data.
b) Two pieces of information are studied and can be plotted on a scatter plot graph. This is 2-variable data.

5. Deciding which type of graph to draw
Dylan conducted a survey about students part-time jobs:
Hours spent at Part-time Job
Student
During the week (h)
On the weekend (h)
Peeta Mellark
0.0
18.0
Katniss Everdeen
5.0
12.5
Hermione Grainger
8.0
12.0
Harry Potter
17.0
Gandalf the Grey
16.5
Dumbledore
10.0
16.0
John Crichton
9.5
Aeryn Sun
15.0
6.0

6. Deciding which type of graph to draw
What graph type would be best to show how many hours each student worked on the weekend? Is this 1 or 2 variable data? Justify.
What type of graph would best show a relationship between weekday and weekend hours worked? Is this 1 or 2 variable data? Justify.
Graph each situation indicated.
Would you expect any correlation in the graph from part b?